Highland Lake is a lake in northeastern Illinois located approximately north of Chicago in Avon Township of unincorporated Lake County. Nearby towns include Grayslake to the east, Round Lake Beach to the north, Round Lake to the west, and Hainesville to the south. Highland Lake is approximately wide at the widest point east to west and north to south. The total area is approximately . with a perimeter of . Common activities including wading, swimming,. fishing, and a variety of non-gas powered watercraft.